Wyss Institute file photo of E. coli. Image: Rick Groleau.
In two parallel projects, researchers have created new genomes inside the bacterium E. coli in ways that test the limits of genetic reprogramming, opening new possibilities for increasing flexibility, productivity and safety in biotechnology.
In one project, researchers created a novel genome—the first-ever entirely genomically recoded organism—by replacing all 321 instances of a specific “genetic three-letter word,” called a codon, throughout the organism’s entire genome with a word of supposedly identical meaning. The researchers then reintroduced a reprogrammed version of the original word (with a new meaning, a new amino acid) into the bacteria, expanding the bacterium’s vocabulary and allowing it to produce proteins that do not normally occur in nature. Continue reading »
Using animal behaviour data to better inform mathematical models of animal movements.
Many animals are adapting to human encroachment of their natural habitats. Carnivores in particular require territories of sufficient size and so are often forced to move between numerous small habitat patches. To date, scientists often use mathematical models to predict these important routes, but fishers fitted with GPS sensors are now showing that their calculations may be missing the mark if they ignore animal behaviour.
Corridors are spaces that receive too little attention and yet are vitally important. How else would we get from the bedroom to the bath or from the couch to the kitchen? Without the hallway in between, we would starve on the sofa, unable to reach our food. In the wild the areas that connect animals’ living spaces are known as corridors. It is vital for the conservation of many species that animals can move freely and safely from their hunting grounds to their mating areas, for example. If a new road is built through the middle of an important corridor, it may put an entire population at risk. Continue reading »
Inspired by the twitching whiskers of common rats and Etruscan shrews, EU-funded researchers have developed rodent-like robots and an innovative tactile sensor system that could be used to help find people in burning buildings, make vacuum cleaners more efficient and eventually improve keyhole surgery.
Sensor systems that replicate the sense of touch have been the focus of increasing research in recent years, largely for robotics applications. But the focus has normally been on developing sensors that in some way or another replicate the way humans touch and sense the world: with our skin and particularly our fingertips. Continue reading »
MSU researchers explore what would happen if computer viruses had to find mates in order to reproduce. Photo illustration by G.L. Kohuth
Computer viruses are constantly replicating throughout computer networks and wreaking havoc. But what if they had to find mates in order to reproduce?
In the current issue of Evolution, Michigan State University researchers created the digital equivalent of spring break to see how mate attraction played out through computer programs, said Chris Chandler, MSU postdoctoral researcher at MSU’s BEACON Center for the Study of Evolution in Action.
“This is actually a big question that still generates a lot of debate,” said Chandler, who co-authored the study with Ian Dworkin, assistant professor of zoology, and Charles Ofria, associate professor of computer science and engineering. “People have some good ideas, but they can be hard to test really well in nature, so we decided to take a different approach.” Continue reading »
The use of synthetic biological systems in research, healthcare, and manufacturing often requires autonomous history-dependent behavior and therefore some form of engineered biological memory. For example, the study or reprogramming of aging, cancer, or development would benefit from genetically encoded counters capable of recording up to several hundred cell division or differentiation events. Although genetic material itself provides a natural data storage medium, tools that allow researchers to reliably and reversibly write information to DNA in vivo are lacking. Here, we demonstrate a rewriteable recombinase addressable data (RAD) module that reliably stores digital information within a chromosome.
By Y. Tanizawa, Y. Okamoto, K. Tsuzuki, Y. Nagao, N. Yoshida, R. Tero, S. Iwasa, A. Hiraishi, Y. Suda, H. Takikawa, R. Numano, H. Okada, R. Ishikawa and A. Sandhu, in J. Phys.: Conf. Ser.352 012011 doi:10.1088/1742-6596/352/1/012011
Abstract: The wide-ranging industrial application of graphene and related compounds has led researchers to devise methods for the synthesis of high quality graphene. We recently reported on the chemical synthesis, patterning, and doping of graphene films by the chemical exfoliation of graphite into graphene oxide (GO) with subsequent chemical reduction into graphene films [1, 2]. Here, we describe a hybrid approach for the synthesis of reduced graphene sheets, where chemically derived GO was reduced by microorganisms extracted from a riverside near the University. Our procedure enabled the production of ~100 μm sized reduced graphene sheets, which showed excellent Raman spectra associated with high quality reduced graphene. We give a detailed account of the relationship between the type of microorganisms and the properties of the resulting reduced graphene.
For NASA’s Martian rovers, it seems that bigger is better. The $2.5 billion (£1.6 billion) Curiosity — which is currently whizzing towards the red planet following its November 2011 launch — is five times bigger than twin predecessors Spirit and Opportunity.
In fact it’s taller than most basketball players at 2.2 meters high, and is about the size of a small SUV with its three-meter length. Add on its humongous robot arm, which can reach out another 2.2 meters, and you’ve got only seriously huge rover.
To power such a beast needs a lot of energy and the robot packs a radioisotope power system that generates electricity from the heat of plutonium’s radioactive decay. It will fuel the enormous rover for at least 687 Earth days (one Martian year).
But at the US Naval Research Laboratory, space roboticists are researching planetary explorers at the other end of the size spectrum. While Curiosity weighs about the same as a giraffe (900kg), these autonomous micro-rovers would be lighter than a bag of sugar, at just one kilogram. Continue reading »
Physicists have found the strongest evidence yet of quantum effects fueling photosynthesis.
Multiple experiments in recent years have suggested as much, but it’s been hard to be sure. Quantum effects were clearly present in the light-harvesting antenna proteins of plant cells, but their precise role in processing incoming photons remained unclear.
In an experiment published Dec. 6 in Proceedings of the National Academy of Sciences, a connection between coherence — far-flung molecules interacting as one, separated by space but not time — and energy flow is established.
“There was a smoking gun before,” said study co-author Greg Engel of the University of Chicago. “Here we can watch the relationship between coherence and energy transfer. This is the first paper showing that coherence affects the probability of transport. It really does change the chemical dynamics.” Continue reading »
New computer chip models how neurons communicate with each other at synapses.
CAMBRIDGE, Mass. — For decades, scientists have dreamed of building computer systems that could replicate the human brain’s talent for learning new tasks.
MIT researchers have now taken a major step toward that goal by designing a computer chip that mimics how the brain’s neurons adapt in response to new information. This phenomenon, known as plasticity, is believed to underlie many brain functions, including learning and memory.
With about 400 transistors, the silicon chip can simulate the activity of a single brain synapse — a connection between two neurons that allows information to flow from one to the other. The researchers anticipate this chip will help neuroscientists learn much more about how the brain works, and could also be used in neural prosthetic devices such as artificial retinas, says Chi-Sang Poon, a principal research scientist in the Harvard-MIT Division of Health Sciences and Technology. Continue reading »